I was very surprised to see that Costco carries Diesel Exhaust Fluid. I was browsing through Costco Business the other day, when I came across this Costco DEF fluid. You can’t beat the price at only $9.39 for 2.5 gallons. Every other big box store (Target, Walmart, O’Reilly’s, etc.) carries this for $12 – $15 … Read more